Biodegradable Sheet Composite for Liquid Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current biodegradable sheets are inadequate for use as long-term food or drink receptacles due to their lack of physical strength, flexibility, low light transmittance, high gas permeability, and short shelf life, making them unsuitable for packaging liquids effectively.
Innovation Solution
A biodegradable sheet comprising a combination of poly(epsilon-caprolactone) (PCL) or polyhydroxyalkanoates (PHA) with other hydrophobic polymers like polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), poly lactic acid (PLA), and polybutylene adipate terephthalate (PBAT), which reduces water vapor and oxygen transmission rates while maintaining mechanical properties and heat sealing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If biodegradable sheets are made from single polymers like PLA or PHBV, then they achieve good mechanical strength, but they become rigid and brittle with poor flexibility
Solution Approach 1:
The patent applies composite materials by combining multiple biodegradable polymers (PLA, PHBV, PCL, PBS, PBAT) in specific ratios to create a sheet that achieves both mechanical strength and flexibility. The composite formulation balances the rigid properties of PLA with the flexible properties of other polymers, resolving the contradiction between strength and flexibility.
2Ease of operation
If flexible biopolymers like PHBV and PBAT are used, then good flexibility is achieved, but they have low melting points and tend to self-adhere and become unstable when exposed to heat
Solution Approach 1:
The patent uses composite materials combining flexible polymers (PHBV, PBAT) with thermally stable polymers (PLA, PCL) in specific ratios. This composite approach maintains the flexibility benefits of PHBV and PBAT while the PLA and PCL components provide thermal stability and prevent self-adhesion when exposed to heat.
Solution Approach 2:
The patent applies parameter changes by carefully controlling the composition ratios of different polymers and processing parameters (cooling rate, crystallization conditions) to optimize both flexibility and thermal stability. By adjusting these parameters, the sheet achieves the desired balance between softness and heat resistance.
3Reliability
If known biodegradable sheets are used for packaging, then environmental sustainability is achieved, but they have high gas permeability and short shelf life making them unsuitable for long-term liquid receptacles
Solution Approach 1:
The patent applies composite materials by combining multiple biodegradable polymers with different barrier properties. The specific combination of PLA, PHBV, PCL, PBS, and PBAT creates a synergistic effect that reduces gas permeability (both oxygen and carbon dioxide) while maintaining biodegradability, thereby extending shelf life for long-term liquid receptacle applications.
4Object-generated harmful factors
If biodegradable sheets are made opaque with barriers, then gas permeability is reduced, but light transmittance decreases and the sheets become less suitable for certain applications
Solution Approach 1:
The patent uses composite materials where the specific polymer combination and their molecular structures provide inherent gas barrier properties without requiring opaque additives. The composite formulation achieves reduced gas permeability while maintaining transparency or translucency, allowing light transmission for applications where visibility is desired.
Data Source
AI summary
Disclosed is a biodegradable sheet comprising at least one layer which is a direct contact layer, intended to successfully contact materials, such as liquids, while maintaining the mechanical properties of the sheet and to extend the biodegradable sheet shelf life. The direct contact layer may comprise a hydrophobic polymer selected from poly(epsilon-caprolactone) (PCL) polyhydroxybutyrate (PHB), Polydioxanone (PDO) polyglycolic acid (PGA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), poly lactic acid (PLA), polybutylene adipate terphtalate (PBAT), polyhydroxyalkanoates (PHA), such as polyhydroxybutyrates (PHB), polyhydroxyvalerates (PHV), and polyhydroxybutyrate-hydroxyvalerate copolymers (PHBV) or any mixture thereof. The biodegradable sheet may further comprise surface treated nanoclay particles, PVOH grafted with a crosslinker and PBS or PBSA The first hydrophobic polymer is present in said at least one layer in an amount of about 30% w/w.